Perfect signaling among three parties violating predefined causal order

Understand

The paradigmatic view where information is seen as a more fundamental concept than the laws of physics leads to a different understanding of spacetime where the causal order of events emerges from correlations between random variables representing physical quantities.

• In particular, such an information-theoretic approach does not enforce a global spacetime structure.
• By following this path, we conclude that perfect signaling correlations among three parties are possible which do not obey the restrictions imposed by global spacetime.
• We show this using a recent framework based on the sole assumptions that locally, quantum theory is valid and random variables can be described by probability distributions.